Is geoengineering a lot of hot air?

Geoengineering was described as a “pretty scary” idea by scientists who have been assessing its ramifications said Ben Kravitz, Carnegie Institute for Science. He has been studying the idea of mimicking the cooling effect of large volcanic eruptions on climate. This could be done by continually pumping sulphates into the atmosphere to reflect sunlight away from earth.

Could we mimic this volcano?Flickr/kahunapulej

He tested two scenarios — releasing suphates at the lowest layer, the troposphere, or the highest, into space. Both cases carried the risk of serious unintended consequences.

Geoengineering is a highly controversial concept since it involves large-scale deliberate manipulation of the planet to remove greenhouse gases in the atmosphere and mitigate global warming. Some of the techniques, such as solar radiation management, are meant to reduce the warming effects of carbon dioxide.

Kravitz said the first idea, put forward in 1977, was to pump carbon dioxide into the deep ocean.

Colin Axon, of Brunel University in the UK, explained that issues included cost (energy, people and investments), materials, process, water and space (land and distribution).

Margaret Torn, head of the Climate and Carbon Sciences Program at Berkeley National Laboratory, US, who studied carbon carbon dioxide removal by terrestrial ecosystems, found that the disadvantages outweighed the advantages if the landscape was altered, for example by intensively planting trees where there used to be none.

But, she said the study showed that “there can be ways to manage land to increase carbon sequestration”.

“There are lots of grey areas in geoengineering” — and so far she said, very few researchers have actually came up with compelling research.

This blog post is part of our Planet Under Pressure 2012 coverage — which takes place 26–29 March 2012. To read news and analysis from the conference please visit our website.